Process for preserving the luster of organic derivatives of cellulose



Patented Dec. 24, 11929 rates mates area Free CAMILLE DREYFUS, OF NEW YORK, N. Y.,

AND HERBERT PLATT, OF CUMBERLAND,

OF DELAWARE PROCESS FOR PRESERVING THE LUSTER OF ORGANIC DERIVATIVES OF CELLULOSE No Drawing.

from some organic derivatives of cellulose is the fact that such material loses its luster when boiled in water or subjected to a boiling treatment such as is commonly encountered in the dyeing, bleaching and similar processes. This characteristic has somewhat limited the application of such fibers, fabrics, etc., particularly when employed in conjunction with cotton, wool, real silk, etc. In the dyeing of cotton and wool it is usually necessary that the dye bath be maintained at or near a boil ing temperature and forthis reason great difficulty was encountered in the dyeing of mixtures ofcotton and or wool with cellulose ace- I in admixture with cotton and/ or wool and/ortate silk because of the consequent deluster-v ing of the cellulose actate silk. The same difficulty is encountered when it is desiredto degum real silk in a mixture of real silk and cellulose acetate silk, since this degumming is usually carried on .at boiling temperature.

The object of this invention is to devise a process for the prevention, total or partial, of the delustering of artificial silk prepared from organic derivatives of cellulose, whether the same be in thread, fiber or fabric form.

Another object of this invention is to prevent the delu'stering of such artificial silk when Application filed December ,30, 1926. Serial N6. 158,127.

cial silk or lessen the amount of delustering which occurs, depending upon the salt and the amount of such salt present in the boiling bath. lhe salts which they havefound to be most elficient in obtaining these results are the sulphocyanides of the alkali and alkaliearth metals.

Sodium sulphocyanide, potassium sulphocyanide, ammonium sulphocyanide, calcium sulphocyanide, barium sulphocyanide have been utilized with varying degrees of success. The choice of the particular salt to be used will depend upon the nature of the bath in which it is desired to use the same. If the salt is to be added to a dye bath in large quantities it will be necessary to add the sodium or potassium sulphocyanide, preferably the former, and similarly when the salt is added to a bath containing soap. At other times the use of calcium sulphocyanide is recommended. The following are some examples of the manner in which the applicants invention can be utilized:

Example I A cellulose acetate fabric was treated at the boil for of an ho ur ina bath containing 10 grams per litre of calcium sulphocyanide. The fabric, after drying, was found to have lost but very little of its original luster.

The fabric after this treatment was found to Ewample [I A cellulose acetate fabric was subjected to a process as outlined in Example I, using 100 grams of calcium sulphocyanide per litre ofbath. The fabric, after drying,- had its original luster.

E wample I I I A fabric of cellulose acetate silk was treated as outlined in Example I, substituting ammonium sulphocyanide for the calcium sulphocyanide. The luster was partly protected by the ammonium sulphocyanide but the protection obtained was not so 'good as the protection obtained using calcium sulphocyanide.

Example I V A process similar to that outlined in Example II, employing ammonium sulphocyanide in the-place of calcium sulphocyanide, was carried out on cellulose acetate fabric. The luster of the fabric was protected but not to the same extent as in Example II.

E wample V A cellulose acetate fabric was treated as in Example I, using 265 grams of ammonium sulphocyanide per litre. The luster of the fabric after this treatment was found to be virtually unaltered.

E zmmple VI A cellulose acetate fabric was treated according to the process outlined in Example I, utilizing 10 grams of sodium sulphocyanide per litre in the place 'of calcium sulphocyani'de. The luster of the fabric, after this treatment, was preserved, but to a lesser degree than it was by the treatments outlined in Examples I and III.

mample A cellulose acetate fabric was treated according to the process outlined in Example I,

utilizing 10 grams of potassiumsulphocyanide per litre in place of calcium salt. The luster ofvthe fabric treated was preserved to about the same extent-as in Example VI.

Ewample VIII A cellulose acetate fabric was treated in a dye bath containing 3% SRA blue III and to which bath had been added 10 grams per litre of sodium sulphocyanide. The fabric was dyed at the boil for one hour. A marked 7 loss in the luster of the fabricwas noticed but I the relustering was not as great as in a similar treatment in the absence of sodium sulpho- ,oyanide. This treatment was repeated in the presence of soap, and it was observed that the fabric suffered a greater loss of luster in the presence of the soap. This indicates that i the protective effect of the 'sulphocyanide is lessened by' the presence of soap.

Example [X A cellulose acetate fabric'was treated in a dye bath containing 3% SRA blue III and to which bath had been added 50 grams per litre of sodium sulphocyanide. The fabric was dyed at 100 C. for one hour. There was a loss of luster in the fabric but itwas not as great as that resulting from the process outlinedin the preceding example and employing but 10 grams per litre of sodium 'sulphocyanide. The hand and appearance of the fabric was superior to that of similar untreated material.

Example X Stockings made from cellulose acetate silk were treated in an open tub at the boil for one hour in a bath containing 10 grams of sulphocyanide per litre. The stockings retained their original luster, had a good full handle and did not show any teethy effect.

Ealample XI Hosiery made from cellulose acetate silk was treated in an open tub at the boil for one hour in a bath containing 8 grams of sodium sulphocyanide per litre. The stockings thus treated were very slightly delustered and had a good full handle. In addition the stockings did not shown any teethy eflect such as usually results when stockings are treated according to this or the preceding example,

but in the absence of sulphocyanides. It will, therefore, be seen that the use-ofs'ulphocya nides, in addition to its protective influence on the luster, results in the prevention of teethiness.

From the above examples it will, therefore,

a be noted that fabrics made from cellulose ace tate and other organic esters and ethers of cellulose can be treated at boiling temperatures without losing their characteristic luster ifthere is added to the boiling solution any of the various salts enumerated. By

varying the salt and quantity of the salt added it is possible to regulate the extent of the delustering. We have found that concentrations of the salt solution used of from 0.1% to 30% are very suitable for this puropse. It is thus possible to obtain the various gradations between a virtually complete delustering and a retention of the normal luster of the fabric.

Of the various sulphocyanides utilized in the above examples the calcium sulpho cyanide appears to be the most eflicacious in preventing the loss-of luster in the organic derivatives Y of cellulose. The ammonium and barium sulphocyanldes are also very good but are not quite as effective as the calcium salt. The

Thus a fabric which is being treated on a jig does not deluster easily whereas the same fabric treated on a winch or reel will deluster. much more easily and most easily if immersed'completely in 'a water or soap and upon the type and construction of the fabric.

Generally speaking yarn will deluster more easily than knitted fabric and knitted fabric in turn will deluster more readily than woven fabric. As a general rule the more dense the fabric or its individual yarns the more difiicult it is to 'deluster the same.

In view of the above the examples given herein are to be taken as examples only and will have to be somewhat modified in utilizing the different machines or different types of fabrics. Where it is found that the luster is not sufliciently protected, suflicient protection can be obtained by increasing, within certain limits, the concentration of the sulphocyanide in the bath.

The great advantage of the processes outlined herein over current practice lies in the fact that the luster of organic derivatives of cellulosesuch as cellulose acetate etc., can be preserved, partially or totally, by employing as little as one to. two percent of calcium sulphocyanide or one to live percent of sodium or potassium sulphocyanide. Before this invention if it was desired to treat cellulose acetate and similar materials in boiling slutions it was necessary to add'large quantities of salt such as Glaubers salt, sodium chloride, etc.,the amounts exceeding in many cases. The presence of these large amounts of salts in the dye bath is troublesome since, among other things, there is a tendency for the dye stuff to be salted out. It is clear'that this draw-back does not exist if the applicants process is utilized since the concentration of the salt rarely exceeds 5%.

By virtue of the ability to regulate, as a result of the applicants process, the amount of delustering which takes place it is possible to obtain cellulose acetate and similar fabrics which very closelyresemble natural silk. This resemblance is very marked not only in the luster but also in the softness and handle of the thus treated fabrics, a feature which has long been desired.

The salts of the classes above specified in addition to having the property of preserving the luster of cellulose acetate and similar artificial silks, have a further desirable eifect on such materials. Vhen used in proper concentrations they act as swelling or 'jelling agents for this class of yarns and 'fabrics. The improvement in the softness and handle and appearance of the fabric when treated with a solution of the salts is probably due to this swelling action of the salts upon the fabric.

The applicants invention is not to be considered as limited by the examples hereinbefore given. The invention is of great importance in the treatment of mixed fabrics made from yarns or threads of organic cellu lose esters and cotton, wool or silk or any of them. As heretofore stated any one or more of the salts enumerated can be utilized in this process, the choice of the particular salt being determined by treatment to which the fabric is being subjected. In addition the quantity of the particular salt added can be varied within a wide range depending upon the extent of delustering of the organic cellulose derivative desired. The percentages as given in the claims are based upon the bath and not upon the fabric or material being treated.

Having described our invention what we claim and desire to secure by Letters Patent 1s:

1. A process of controlling the delustering of materials comprising organic derivatives of cellulose which consists in adding to a hot bath in which such delustering is apt to occur. a salt of the formula RCNS, where R denotes ammonium or a metal of the alkaline or alkaline-earth series.

2. process of protecting the luster of materials comprising organic derivatives of cellulose which consists iii adding to a hot bath in which delustering of such material is apt to occur, a sulphocyanide of an alkaliearth metal.

3. A process of protecting the luster of materials comprising organic derivatives of cellulose which consists in adding to a hot bath in which delustering of such material is apt to occur, sulphocyanide of calcium.

.4. A process of preserving the luster of materials comprising organic esters of cellulose which consists in adding to a hot bath in which delustering of such material is apt to occur, a saltof the formula RCNS, where R denotes ammonium or a metal of the alkaline or alkaline-earth series.

5. A process of controlling the delustering of materials comprising organic esters of cellulose which consists in adding to a hot bath in which such delustering is apt to occur, a sulphocyanide of an alkali-earth metal.

6. A process of controlling the delustering of materials comprising organic esters of cellulose which consists in adding to a hot bath in which such delustering is apt to occur, sulphocyanide of calcium.

7. A process of preserving the luster of materials containing cellulose acetate which comprises adding to a hot bath in which delustering is apt to occur, a salt of the formula RCNS, where R denotes ammonium or a metal ofthe alkaline or alkaline-earth series.

8. A process of controlling the delustering of materials containing cellulose acetate which comprises adding to a hot bath in which such delustering is apt to occur, a sulphocyanidc of an alkali-earth metal.

9. A process of protecting the luster of materials containing cellulose acetate which comprises adding to a hot bath in which decur 0.1%30% of a salt having the formula 'RCNS, where R denotes ammonium or a -1netal of the alkaline or alkaline-earth series.

11. A process of protecting the luster of filaments and fabrics of organic esters of cellulose which comprises adding to a hot bath in which delustering of such material is apt to occur 0.1%10% of a sulphocyanide of an alkali-earth metal. I

12. A process of preserving the luster of filaments and fabrics of organic esters of cellulose which comprises adding to a hot bath in which delustering of such material is apt to occur 0.1%10% of calcium sulphocyanide.

13. A process of controllingthe delustering of filaments and fabrics of organic esters of cellulose which comprises adding to a hot bath in which such delustering is apt to occur 1% of a salt having the formula RCNS, where R denotes ammonium or a metal of the alkaline or alkaline-earth series.

14. A process of protecting the luster of filaments and fabrics of organic esters of cellulose which comprises adding to a hot bath in which delustering of such material is apt to occur, 1% of a sulphocyanide of'an alkali-earth metal.

15. A process of preserving the luster of filaments and fabrics of organic esters of cel-- lulose which comprises adding to a-hot bath in which delustering of such material is apt to occur, 1% of calcium sulphocyanide.

16. In a process for the dyeing of mixed fabrics containing organic esters of cellulose at elevated temperatures the step of adding to the dye bath a salt of the formula R-CNS,

where R denotes ammonium-or a metal of the alkaline or alkaline-earth series, whereby the luster of the organic derivative of cellulose is preserved.

17. In a process for the'dyeing of mixed fabrics containing organic esters of cellulose v at elevated temperatures the step of adding to the dye bath a sulphocyanide of an alkaliearth metal, whereby the luster of the organic derivative of cellulose is protected.

18. Ina process for the dyeing of mixed fabrics containing organic esters of cellulose at elevated temperatures the step of adding to .the dye bath calcium sulphocyanide, whereby the luster of the organic derivative of cellulose is, preserved.

19. In a process for the dyeing of mixed fabrics containing cellulose acetate at elevated temperatures the 'step of adding to the J dye bath calcium sulphocyanide, whereby the luster of the organic derivative of cellulose is protected.

mixed 20.'In a process for the'dyeing of at elefabrics containing cellulose acetate vated temperatures the step of adding to the 

